Semiconductor transistors, in particular field-effect controlled switching devices such as a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) or an Insulated Gate Bipolar Transistor (IGBT) have been used for various applications including but not limited to use as switches in power supplies and power converters, electric cars, air-conditioners, and even stereo systems. Particularly with regard to power devices capable of switching large currents and/or operating at higher voltages, low switching losses are often desired. In order to reduce switching losses, there are ongoing developments to reduce distances between neighboring unit cells of power devices. For example, the lateral distance between a trench gate electrode and the contact to source region and body region of the transistor may be reduced. However, this may require a high-precision deep UV-technology and a further contact layer with tight alignment tolerances. Therefore, manufacturing of such devices is often very complex and costly.
Accordingly, there is a need to provide reliable and cost-effective methods for forming contacts of semiconductor transistors.